The text was to be sent to governments for approval overnight, and a vote is now expected at 11:00 local time (15:00 GMT) on Saturday.

"There was a negotiation, there is not yet an agreement," French UN Ambassador Gerard Araud told reporters. "It's very tough, but there will be a vote in any case."

US ambassador to the UN Susan Rice said it "would be wise not to make predictions" on the outcome.

The resolution calls for the deployment of an advance team of 30 monitors. Additional approval will be required to increase the deployment to 250, the total which Mr Annan is seeking.

A spokesman for Mr Annan has said that a small group of observers is ready to leave for Syria as soon as a resolution is passed.

"At the moment we have the advance team standing by to board planes and to get there, to get themselves on the ground as soon as possible," Ahmad Fawzi said.

Earlier, President Barack Obama authorised an increase in US aid for Syria's "non-violent, political opposition", including communications equipment and medical supplies, officials said.

Lower casualties

Prayers on Friday were seen as a major test for the truce. Several deaths were reported as thousands of protesters poured out of mosques and took to the streets across the country in fresh revolt against President Bashar al-Assad.

Annan's six-point peace plan

1. Syrian-led political process to address the aspirations and concerns of the Syrian people

2. UN-supervised cessation of armed violence in all its forms by all parties to protect civilians

3. All parties to ensure provision of humanitarian assistance to all areas affected by the fighting, and implement a daily two-hour humanitarian pause

4. Authorities to intensify the pace and scale of release of arbitrarily detained persons

5. Authorities to ensure freedom of movement throughout the country for journalists

6. Authorities to respect freedom of association and the right to demonstrate peacefully

Activists reported that the number of demonstrations nationwide - more than 750 - was higher than on any Friday since the revolt began 13 months ago.

The opposition said security forces fired into the air in many places to prevent or disperse protests. But in others, protesters were killed by gunfire.

But our correspondent says the overall casualty figures for Friday were very much lower than many had feared.

In general, he says, the ceasefire has brought a sharp drop in the level of violence and deaths but, with troops, tanks and heavy weaponry still deployed in and around population centres, it is still very fragile and there are many ways in which it could unravel.